Opioids Inhibit Lateral Amygdala Pyramidal Neurons by Enhancing A Dendritic Potassium Current

Pyramidal neurons in the lateral amygdala discharge trains of action potentials that show marked spike frequency adaptation, which is primarily mediated by activation of a slow calcium-activated potassium current. We show here that these neurons also express an alpha-dendrotoxin- and tityustoxin-Kalpha-sensitive voltage-dependent potassium current that plays a key role in the control of spike discharge frequency. This current is selectively targeted to the primary apical dendrite of these neurons. Activation of mu-opioid receptors by application of morphine or D-Ala(2)-N-Me-Phe(4)-Glycol(5)-enkephalin (DAMGO) potentiates spike frequency adaptation by enhancing the alpha-dendrotoxin-sensitive potassium current. The effects of mu-opioid agonists on spike frequency adaptation were blocked by inhibiting G-proteins with N-ethylmaleimide (NEM) and by blocking phospholipase A(2). Application of arachidonic acid mimicked the actions of DAMGO or morphine. These results show that mu-opioid receptor activation enhances spike frequency adaptation in lateral amygdala neurons by modulating a voltage-dependent potassium channel containing Kv1.2 subunits, through activation of the phospholipase A(2)-arachidonic acid-lipoxygenases cascade.

Functional maturation of isolated neural progenitor cells from the adult rat hippocampus

Although neural progenitor cells (NPCs) may provide a source of new neurons to alleviate neural trauma, little is known about their electrical properties as they differentiate. We have previously shown that single NPCs from the adult rat hippocampus can be cloned in the presence of heparan sulphate chains purified from the hippocampus, and that these cells can be pushed into a proliferative phenotype with the mitogen FGF2 [Chipperfield, H., Bedi, K.S., Cool, S.M. & Nurcombe, V. (2002) Int. J. Dev. Biol., 46, 661-670]. In this study, the active and passive electrical properties of both undifferentiated and differentiated adult hippocampal NPCs, from 0 to 12 days in vitro as single-cell preparations, were investigated. Sparsely plated, undifferentiated NPCs had a resting membrane potential of approximate to -90 mV and were electrically inexcitable. In > 70%, ATP and benzoylbenzoyl-ATP evoked an inward current and membrane depolarization, whereas acetylcholine, noradrenaline, glutamate and GABA had no detectable effect. In Fura-2-loaded undifferentiated NPCs, ATP and benzoylbenzoyl-ATP evoked a transient increase in the intracellular free Ca2+ concentration, which was dependent on extracellular Ca2+ and was inhibited reversibly by pyridoxalphosphate-6-azophenyl-2'-4'-disulphonic acid (PPADS), a P2 receptor antagonist. After differentiation, NPC-derived neurons became electrically excitable, expressing voltage-dependent TTX-sensitive Na+ channels, low- and high-voltage-activated Ca2+ channels and delayed-rectifier K+ channels. Differentiated cells also possessed functional glutamate, GABA, glycine and purinergic (P2X) receptors. Appearance of voltage-dependent and ligand-gated ion channels appears to be an important early step in the differentiation of NPCs.

Fractal analysis of pyramidal cells in the visual cortex of the galago (Otolemur garnetti): Regional variation in dendritic branching patterns between visual areas

Previously it has been shown that the branching pattern of pyramidal cells varies markedly between different cortical areas in simian primates. These differences are thought to influence the functional complexity of the cells. In particular, there is a progressive increase in the fractal dimension of pyramidal cells with anterior progression through cortical areas in the occipitotemporal (OT) visual stream, including the primary visual area (V1), the second visual area (V2), the dorsolateral area (DL, corresponding to the fourth visual area) and inferotemporal cortex (IT). However, there are as yet no data on the fractal dimension of these neurons in prosimian primates. Here we focused on the nocturnal prosimian galago (Otolemur garnetti). The fractal dimension (D), and aspect ratio (a measure of branching symmetry), was determined for I I I layer III pyramidal cells in V1, V2, DL and IT. We found, as in simian primates, that the fractal dimension of neurons increased with anterior progression from V1 through V2, DL, and IT. Two important conclusions can be drawn from these results: (1) the trend for increasing branching complexity with anterior progression through OT areas was likely to be present in a common primate ancestor, and (2) specialization in neuron structure more likely facilitates object recognition than spectral processing.

Establishing representative no-take areas in the Great Barrier Reef : Large scale implementation of theory on marine protected areas

The Great Barrier Reef Marine Park, an area almost the size , of Japan, has a new network of no-take areas that significantly improves the protection of biodiversity. The new marine park zoning implements, in a quantitative manner, many of the theoretical design principles discussed in the literature. For example, the new network of no-take areas has at least 20% protection per bioregion, minimum levels of protection for all known habitats and special or unique features, and minimum sizes for no-take areas of at least 10 or 20 kat across at the smallest diameter Overall, more than 33% of the Great Barrier Reef Marine Park is now in no-take areas (previously 4.5%). The steps taken leading to this outcome were to clarify to the interested public why the existing level of protection wets inadequate; detail the conservation objectives of establishing new no-take areas; work with relevant and independent experts to define, and contribute to, the best scientific process to deliver on the objectives; describe the biodiversity (e.g., map bioregions); define operational principles needed to achieve the objectives; invite community input on all of The above; gather and layer the data gathered in round-table discussions; report the degree of achievement of principles for various options of no-take areas; and determine how to address negative impacts. Some of the key success factors in this case have global relevance and include focusing initial communication on the problem to be addressed; applying the precautionary principle; using independent experts; facilitating input to decision making; conducting extensive and participatory consultation; having an existing marine park that encompassed much of the ecosystem; having legislative power under federal law; developing high-level support; ensuring agency Priority and ownership; and being able to address the issue of displaced fishers.

Automated layout of small lattices using layer diagrams

Good quality concept lattice drawings are required to effectively communicate logical structure in Formal Concept Analysis. Data analysis frameworks such as the Toscana System use manually arranged concept lattices to avoid the problem of automatically producing high quality lattices. This limits Toscana systems to a finite number of concept lattices that have been prepared a priori. To extend the use of formal concept analysis, automated techniques are required that can produce high quality concept lattice drawings on demand. This paper proposes and evaluates an adaption of layer diagrams to improve automated lattice drawing. © Springer-Verlag Berlin Heidelberg 2006.

Expression and role of complex carbohydrates in axon guidance in the olfactory system

Primary sensory neurons in the vertebrate olfactory systems are characterised by the differential expression of distinct cell surface carbohydrates. We show here that the histo-blood groups Sda (or CT1 antigen) and H are expressed by primary sensory neurons in the olfactory system, while the blood group A carbohydrate is expressed by a subset of vomeronasal neurons only in the developing accessory olfactory system. We have used both loss-of-function and gain-of-function approaches to manipulate expression of these carbohydrates in the olfactory system. In null mutant mice lacking the alpha(1,2)fucosyltransferase FUT1, the blood group H and A carbohydrates were not expressed in the olfactory systems which caused delayed development of the nerve fibre and glomerular layers in the main olfactory bulb. In contrast, ubiquitous expression of blood group A on olfactory axons in gain-of-function transgenic mice perturbed the ability of vomeronasal axons to terminate in the accessory olfactory bulb and affected the selective targeting of axons in the main olfactory bulb. During regeneration following bulbectomy, vomeronasal axons were unable to effectively sort out from the main olfactory axons when blood group A was misexpressed. These results provide in vivo evidence for a role of specific cell surface carbohydrates during development and regeneration of the olfactory nerve pathways.

Genetic manipulation of blood group carbohydrates alters development and pathfinding of primary sensory axons of the olfactory systems

Primary sensory neurons in the vertebrate olfactory systems are characterised by the differential expression of distinct cell surface carbohydrates. We show here that the histo-blood group H carbohydrate is expressed by primary sensory neurons in both the main and accessory olfactory systems while the blood group A carbohydrate is expressed by a subset of vomeronasal neurons in the developing accessory olfactory system. We have used both loss-of-function and gain-of-function approaches to manipulate expression of these carbohydrates in the olfactory system. In null mutant mice lacking the alpha(1,2)fucosyltransferase FUT1, the absence of blood group H carbohydrate resulted in the delayed maturation of the glomerular layer of the main olfactory bulb. In addition, ubiquitous expression of blood group A on olfactory axons in gain-of-function transgenic mice caused mis-routing of axons in the glomerular layer of the main olfactory bulb and led to exuberant growth of vomeronasal axons in the accessory olfactory bulb. These results provide in vivo evidence for a role of specific cell surface carbohydrates during development of the olfactory nerve pathways. (c) 2006 Elsevier Inc. All rights reserved.

Learnability and discriminability of melodic medical equipment alarms

Melodic alarms proposed in the IEC 60601-1-8 standard for medical electrical equipment were tested for learnability and discriminability. Thirty-three non-anaesthetist participants learned the alarms over two sessions of practice, with or without mnemonics suggested in the standard. Fewer than 30% of participants could identify the alarms with 100% accuracy at the end of practice. Confusions persisted between pairs of alarms, especially if mnemonics were used during learning (p = 0.011). Participants responded faster (p < 0.00001) and more accurately (p = 0.002) to medium priority alarms than to high priority alarms, even though they rated the high priority alarms as sounding more urgent (p < 0.00001). Participants with at least 1 year of formal musical training identified the alarms more accurately (p = 0.0002) than musically untrained participants, and found the task easier overall (p < 0.00001). More intensive studies of the IEC 60601-1-8 alarms are needed for their effectiveness to be determined.

Transdermal drug delivery: Basic principles for the veterinarian

The use of topical pharmaceutical formulations is increasingly popular in veterinary medicine. A potential concern is that not all formulations are registered for the intended species, yet current knowledge strongly suggests that simple extrapolation of transdermal drug pharmacokinetics and pharmacodynamics between species, including humans, cannot be done. In this review, an overview is provided of the underlying basic principles determining the movement of topically applied molecules into and through the skin. Various factors that may affect transdermal drug penetration between species, between individuals of a particular species and regional differences in an individual are also discussed. A good understanding of the basic principles of transdermal drug delivery is critical to avoid adverse effects or lack of efficacy when applying topical formulations in veterinary medicine. (c) 2005 Elsevier Ltd. All rights reserved.

Community broadcasting and the enclosure of the public sphere

One of the normative tenets of the Habermasian public sphere is that it should be an open and universally accessible forum. In Australia, one way of achieving this is the provision for community broadcasting in the Broadcasting Services Act. A closer examination of community broadcasting, however, suggests practices that contradict the idea of an open and accessible public sphere. Community broadcasting organizations regulate access to their media assets through a combination of formal and informal structures. This suggests that the public sphere can be understood as a resource, and that community broadcasting organizations can be analysed as ‘commons regimes’. This approach reveals a fundamental paradox inherent in the public sphere: access, participation and the quality of discourse in the public sphere are connected to its enclosure, which limits membership and participation through a system of rules and norms that govern the conduct of a group. By accepting the view that a public sphere is governed by property rights, it follows that an open and universally accessible public sphere is neither possible nor desirable.

Integrating formal specification and software verification and validation

It is not surprising that students are unconvinced about the benefits of formal methods if we do not show them how these methods can be integrated with other activities in the software lifecycle. In this paper, we describe an approach to integrating formal specification with more traditional verification and validation techniques in a course that teaches formal specification and specification-based testing. This is accomplished through a series of assignments on a single software component that involves specifying the component in Object-Z, validating that specification using inspection and a specification animation tool, and then testing an implementation of the specification using test cases derived from the formal specification.

Emerging Structures of Farmer Cooperatives in Vietnam: Case studies from the Mekong Delta

Four farmer groups for mango production and marketing were formed in 2002 in southern Vietnam in response to government support for the creation of market oriented farmer cooperatives. The role and structure of these groups is considered in terms of the degree to which they conform to internationally recognised principles for cooperative formation. Each of the farmer groups studied has evolved in different ways and their degree of compliance with the principles of cooperation varies widely. It is evident that state intervention and market forces may give rise to cooperative structures that differ from that intended under the principles surrounding cooperative law.

A formal metamodeling approach to a transformation between the UML state machine and object-z

A significant problem with currently suggested approaches for transforming between models in different languages is that the transformation is often described imprecisely, with the result that the overall transformation task may be imprecise, incomplete and inconsistent. This paper presents a formal metamodeling approach for transforming between UML and Object-Z. In the paper, the two languages are defined in terms of their formal metamodels, and a systematic transformation between the models is provided at the meta-level in terms of formal mapping functions. As a consequence, we can provide a precise, consistent and complete transformation between them.

Farming under constrained budgets: Practices of agricultural credit users in central Lombok, Indonesia

There has been a long dependency on credit by Indonesian farmers as a result of the lack of capital to apply proper farming practices. This paper describes the farming activities applied by agricultural credit users in Central Lombok, Indonesia. A survey was conducted during July 2001- March 2002 of 65 farmers making use of government or private credit in three villages within the Regency. Data from the farmers were collected using face-to-face, semi-structured interviews. Survey results indicated that on average, farmers had some 20 years experience of farming, were aged 40 years, but lacked of formal education. Their main asset was cropping land with average landholding of 0.69 ha. As a consequence of their capital constraints, farmers were commonly making use of credit to finance their farming activities, including both production of rice as the main crop and secondary crops. Farmers generally applied less than recommended amount of inputs in their farming practices, since the amount of credit they obtained was limited. As a result, their farms become less productive and their repayment capability of loans diminished. Of 65 farmers interviewed, 54 could earn extra income by engaging in a variety of non-farm activities, which contributed on average some 36% to family incomes of over Rp 5 million (A$ 1 thousand). The average credit repayment rate made by agricultural producers was 60%. The repayment made did not always reflect farm production capacity, being sometimes supported by other borrowings. The greater role of credit is not in increasing agricultural production or improving farmers’ income, but in helping them to sustain farm production and their living. Farmers need a bigger amount of credit to make an impact on their livelihood. This should be accompanied by extension services for farmers to enable better use of credit and to change their attitude towards it. As well, farmers require to be equipped with technical and market skills to run a business. Interdisciplinarity, holistic analysis, and an expansion of traditional ‘agricultural’ interests to embrace the span of interests included in rural livelihood, are each critical features of revision of the existing system.

A OCUPAÇÃO RACIONAL DA ARTE NA EDUCAÇÃO FORMAL: UM ESTUDO DESDE A PERSPECTIVA DA CRIATIVIDADE

A arte e a atividade criativa são alguns dos ingredientes essenciais para o crescimento individual, social e cultural do ser humano e, em consequência, da humanidade. Contudo, desde o século XVI vivemos fortemente influenciados pelos parâmetros da racionalidade cognitivo-instrumental. Particularmente na cultura ocidental tem sido predominante a supervalorização da objetividade, da racionalidade e das ciências duras em detrimento da criação artística. Esta pesquisa examina a ocupação racional da arte e sua influência na limitação da criatividade no ambiente escolar. Assim, analisa as diversas concepções de criatividade, à luz da evolução histórica e as influências herdadas do contexto sóciocultural. Considera ainda o conceito de Arte/Educação em sua relação com as condições históricas da inserção da educação formal no Brasil. Finalmente, esta dissertação identifica as marcas da racionalidade em processos educacionais correntes no Brasil, tendo como referência teorias contemporâneas. As conclusões deste trabalho poderão servir como base para fornecer subsídios à reflexão sobre a necessidade de renovação dos olhares sobre a criatividade, como instrumento de formação intelectual, no ensino de artes no contexto escolar.